됐다= already done(완료형 또는 과거형) 아직 8시도 안 됐는데 벌써 자니? From the original sentence, the direct translation will be as follows; Are you going to bed already, even it’s not 8pm yet? (or Are you going to bed already even it’s before 8pm?) 안(않)= not(부정문) 됐다(되었다) = already done(완료형 또는 과거형) So in this sentence, a person is going to bed before 8pm, which is early for sleeping for someone. So at that certain point of time, 8pm is not came yet, the other person is using negative sentence to describe the early time for sleeping. I’m not a teacher, but I hope this would help u!

I believe that word means “cannot”